This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Describe the following: a. convex mirror b. concave mirror |
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Answer» 1.CONVEX MIRROR-THE MIRROR A SPHERICAL REFLECTING SURFACE (OR ANY REFECTING SURFACE FASIONED INTO A PORTION OF A SPHERE) IN WHICH ITS BULGING SIDE FACES THE SOURCE OF LIGHT.2. CONCAVE MIRROR- Acurved mirror is a mirror with acurved reflecting surface .Explanation:HOPE ITS HELP YOU.....PLEASE MARK IN BRAINLIST ANS WER |
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| 3. |
what happens to the resistance of the material if it's length is doubled and area is reduced by half? |
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Answer» its RESISTANCE will FOURTH of the INITIAL |
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| 4. |
4. State some of the practical applications of relative density. |
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Answer» IT IS USED IN LAVA LAMPSGENERALLYKNOWN as "FLUID MOTION LAMPS",IT IS AN illustration of density and BUOYANCY in action as the blobs of oozing goo MOVE up and down in ever-changing shapes. These lamps consist of a container of water in which is PLACED a colored organic oily liquid that does not mix with water, thus constituting a second phase. The composition of the oil phase is such that its density is slightly greater than that of water at room temperature, so it normally resides at the bottom of the container. When the lamp is turned on, a heat source concealed in the base of the container heats the oil phase. This reduces its density to a VALUE below that of the water, causing blobs of oil to rise to the TOP of the container. Being now far removed from the heat source, the blobs cool down and sink back to the bottom, where they repeat the cycle.Explanation:HOPE THIS HELPS YOU |
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| 5. |
Plz help me fast.... |
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Answer» This is the right answerExplanation:I didn't understood the second term and therefore didn't MEAN to confuse you!!!!HOPE THIS HELPS!!!!PLEASE MAKE IT BRAINLIEST ANSWER!!!! |
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| 6. |
Whuch dimensional constant have dimendion of mass is -1 |
| Answer» MASS,m kg, LENGTH,l m,TIME,t electric CURRENT,EC I,a | |
| 7. |
a bus starts from rest on a straight road and acceleration uniformly for 5 second what is the acceleration if its velocity at the end of these 5sec in 25cm/s |
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Answer» tion: acceleration = 5 cm / sec²initial velocity=u= 0final velocity = V= 25 cm/sectime = t= 5 secondsacceleration = a=?v= u+at25 = 0 + a×5=> a = 25/5 = 5CM /sec² |
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| 8. |
A bucket of hot water and a burning matchsticks which contains more amount of heat and has higher temperature |
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Answer» The burning matchstick would obviously have the higher TEMPERATURE, but the total heat content above ABSOLUTE ZERO would be way higher for the bucket full of hot WATER. Simply stated the very small MASS of the matchstick keeps it from containing very much total heat at all in comparison to the much larger mass of the hot water. Hope that it will help you ✌️ |
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| 9. |
A concave mirror has a focal length of 25 cm. At which of the following distance should a solar furnace be placed to concentrate heat energy. a) 45 cm b) 50 cm c) 25 cm d) 30 cm |
| Answer» EXPLANATION:B | |
| 10. |
In the Pressure versus Volume graph shown, in the process of going from a to b 60 J of heat is added, and in the process of going from b to d 20 J of heat is added. In the process of going from a to c to d, what is the total heat added |
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| 11. |
Calcccalculate coulomb force between two alpha part |
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Answer» Calculate coulomb force between two alphaparticles SEPARATED by 3.2×10^-15m?DISTANCE = r =CHARGE on the ALPHA particle = +2e = |
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| 12. |
A body of mass 50g has a heat capacity of 3cal/°C. What will be the specific heat capacity of that body |
| Answer» LET subscript 1 denote solid (hot BODY) and subscript 2 denote water (cold body)Initial temp. of solid T₁=150°CMass of solid m₁ = 50 g = 0.05 KgInitial temp. of water T₂=11°CMass of water m₂= 100 g = 0.1 KgFinal temp of both T= 20°CSpecific HEAT capacity of water c₂=4.2 J/g°C Let Specific heat capacity of solid be c₁now,heat gained by water = heat lost by solidheat gained/lost = mcΔT∴ m₁c₁ΔT₁ = m₂c₂ΔT₂⇒ 0.05*c₁*(150-20) = 0.1*4.2*(20-11)⇒ 0.05*130*c₁ = 0.1*4.2*9⇒ c₁ = 0.5815 J/g°CAnswer: Specific heat capacity of the solid is 0.5815 J/g°C .Explanation: | |
| 13. |
Study of fossils is an important aspect of study of evolution justify answer |
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Answer» Study of fossils is an important aspectof the study of evolution. Fossils are the dead remains or impressions of ORGANISMS which lived in the past. They provide us direct evidence of organic evolution. ... This SHOWS theevolutionary RELATIONSHIP between BIRDS and REPTILES. |
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| 14. |
A parallel plate capacitor has plate area of 10 cm^3and a separation of 0.885mm bw the plate find the capacitance |
| Answer» AREA of each plates (A) = 10 cm² or (10)^-1 m²Distance b/w TWO plates (d) = 0.885 mm or 8.85 × (10)^-4 mWe KNOW that , The capacitance of parallel plates is given byThus ,HENCE , the capacitance of parallel plate capacitor is 1 × (10)^-9 | |
| 15. |
Is holding a pen is a fluid friction |
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Answer» No HOLDING a PEN is not a FLUID friction.Mark as BRAINLIEST |
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| 16. |
2nd and 3rd question. This question is of STD: 10th Subject: Physics Board:ICSE |
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Answer» ng to the law of CONSERVATION of MECHANICAL energy, whenever there is an intercharge between the POTENTIAL energy and kinetic energy,the total mechanical energy i.e.,K+U=constant when there are no FRICTIONAL forces. |
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| 17. |
If object distance is 12cm and image distance is 48 cm then find magnification in concave mirror |
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Answer» Explanation:OBJECT DISTANCE, U = - 12 CM IMAGE DISTANCE, V = - 48 CM MAGNIFICATION = - (V/U)MAGNIFICATION = - (48/12)MAGNIFICATION = - 4 REAL MAGNIFIED IMAGE IS OBTAINED. HOPE THIS HELPS. |
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| 18. |
The energy levels of an atom of element Xare shown in figure. Which one of the leveltransistors will result in the emission of pho-tons of wavelength 620 nm ? Support youranswer with mathematical calculations. ( -10 eV-3 eV-1 eV0 eV) |
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Answer» is 200 NM PLEASE MARK me as BRAINLIEST |
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| 19. |
Derive the escape speed |
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Answer» Derivation of Escape Speed The derivation starts with the initial gravitational potential energy at the given altitude and the initial kinetic energy of the object. This total initial energy is then compared with the sum of the potential and kinetic energies at an infinite separation, in order to determine the escape velocity equationThe Law of Conservation of Energy states that the total energy of a closed system remains constant. In this CASE, the closed system CONSISTS of the two objects with the gravitational force between them and no outside energy or force affecting either object. Thus the total final energy—potential energy plus kinetic energy—must equal the total initial energy:TEi = TE∞KEi + PEi = 0Substitute values: mve2/2 − GMm/Ri = 0Add GMm/Ri to both sides of equation: mve2/2 = GMm/RiSolve for ve2: ve2 = 2GM/Ri TAKE the square root of each expression to get: ve = ± √(2GM/Ri) Considering our gravitational convention for DIRECTION, ve is upward or away from the other object and is thus negative: ve = − √(2GM/Ri)The derivation of the gravitational escape velocity of an object from a much larger mass is achieved by comparing the potential and kinetic energy values at some given point with the values at infinity, applying the Law of Conservation of Energy. The equation for the gravitational escape velocity is:object from a much larger mass is achieved by comparing the potential and kinetic energy values at some given point with the values at infinity, applying the Law of Conservation of Energy. The equation for the gravitational escape velocity is:ve = − √(2GM/Ri) Taking altitude into account, the equation can be written as: ve = − √[2GM/(R + h)] l ve = − √[2GM/(r + h)]Explanation: |
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| 20. |
Define luminous object |
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Answer» A luminous object is ONE that GIVES off light. In other words, it glows (or SHINES) of its own accord. To be able to GLOW, the object must have its own source of energy.❤ |
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| 22. |
What is mean by mirages |
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Answer» an understanding between tow person for TAKE the RESPONSIBILITY of WHOLE FAMILY |
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| 23. |
a rectangular channel carries 2m3/s of water with velocity 1.2m/s. The depth is one-half the width and the Manning coefficient is 0.02. Determine the width of the channel and the depth of the water and the slope of the channel |
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Answer» Hambani rskrhzmrhzmrhz! THA! tha! TH! th! th! TJ's! jgxkgcjgxdktxjxjtx |
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| 24. |
If the time period of a satellite is related to the acceleration due to gravity gradius of the orbit 'r' and the mass of the satellite 'm'according to the equation T=Kr'g'm? where K is a dimensionless constant, Find the values of x,y,z. |
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Answer» The MOTION of OBJECTS is GOVERNED by Newton's LAWS. The same simple laws that govern the motion of objects on earth ALSO extend to the heavens to govern the motion of planets, moons, and other satellites. |
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| 25. |
Question6StatetheLawofConservationofMomentum |
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Answer» The law of conservation of momentum states that for two objects colliding in an ISOLATED system, the total momentum before and after the COLLISION is equal. This is because the momentum LOST by one OBJECT is equal to the momentum gained by the other.plz mark me as BRAINLIEST plz |
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| 26. |
Calculate the gravititio al force due to the earth and mahendra in the earlier example |
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Answer» Hope this help you mate Mark as brainlist The gravitational force between a mass and the Earth is the OBJECT's weight. Mass is CONSIDERED a measure of an object's inertia, and its weight is the force exerted on the object in a gravitational field. On the surface of the Earth, the TWO forces are related by the ACCELERATION due to GRAVITY: Fg = mg. |
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| 27. |
What is difference between insulator and conductor |
| Answer» INSULATOR is a substance through which the HEAT does not pass and CONDUCTER is a substance through the heat is passed | |
| 28. |
Given v=0.6-0.3 in SI units then the intial velocity and acceleration are |
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Answer» tion:HOPE it is useful thank my answers and MARK my ANSWER brainliest |
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| 31. |
Gavitational constant units in Newton |
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Answer» In SI units its VALUE is approximately 6.674×10−11 m3⋅kg−1⋅s−2. The MODERN NOTATION of Newton's law involving G was INTRODUCED in the 1890s by C. V.HOPE IT HELPED U.. |
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| 33. |
The below attachement.. from chapter current electricity |
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Answer» tion:EQUIVALENT RESISTANCE will be five .so ACC. to QUESTION .V=IR I=12\5 |
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| 34. |
Is pressure greater 10m below the sea or 20m below sea |
| Answer» PRESSURE is greature 20 m below the sea bcoz WATER molecules are cold and heavy and they SINK below.that is the reason why air is very thin in mountains and it is humid in coastal areas | |
| 35. |
Name two factor on which focal length of th lens depand |
| Answer» REFRACTIVE INDEX of the glassCurvature of it's TWO SURFACES. | |
| 36. |
From this graph obtain position time relation |
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| 37. |
In a phase shift oscillator R= 2mega ohm and C= 34 mf what is frequency of oscillations..? |
| Answer» PHASE SHIFT =180 DEGREE and 180+180= 360 and 60×3=180 then | |
| 38. |
Derive the relation V is equal to under root rg tan theta for banking of roàds. |
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Answer» o ATTACHMENT: |
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| 39. |
Can anyone answer this |
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Answer» Wave frequencyEXPLANATION:The REASON being, this wave EQUATION is of the GENERAL form/boxed{Y=Asin(wt-kx)}Here w=2πf where 'f' is wave frequencyHope this answer helped you ✌️ |
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| 40. |
Derive the relation V is equal to r omega |
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Answer» here is the DERIVATION EXPLANATION:THANK you |
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| 41. |
Is any work done by a force used to carry handbag, if the person is walking on : a. level road. b. climbing stairs |
| Answer» LEVEL ROAD is the ANSWER. | |
| 42. |
a train traveling at 20ms accelerates at0.5ms calculate the time interval in which it covers distance of 825m |
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Answer» In order to ANSWER this question, we must apply newton's first equation of motion v = u + at Where v is the final velocity in m/s, which is we shall attempt to find, u is the initial velocity in m/s, given in the question as 20m/s a is the acceleration of the body in m/s2, in the question, it is indicated to be 4m/s2 t is the time in SECONDS, from the question, it is 4s. v = 20 + 4*4 v = 20 + 16 = 36m/s As for the distance, either the second or third equation of motion can be used. Using the second equation, s (distance) = u*t + 0.5*a*(t^2) s = 20*4 + 0.5*4*(4*4) s = 80 + 32 = 112m Using the third equation of motion, v2 = U2 + 2as 36^2 = 20^2 + 2*4*s 1296 = 400 + 8 * s 8*s = 1296 - 400 = 896 s = 896/8 = 112mExplanation: |
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| 43. |
Derive equations of motion (Simple Method) |
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Answer» re mainly three equations of motion which describe the relationship between velocity, time, acceleration and displacement.First, consider a body moving in a straight line with uniform acceleration. Then, let the initial velocity be u, acceleration be a, time period be t, velocity be v, and the distance travelled be S.The equation of motions derivation can be done in three ways which are:Derivation of equations of motion by Simple Algebraic MethodDerivation of Motion by Graphical MethodDerivation of Motion by CALCULUS MethodBelow, the equations of motion are derived by all the three methods in a simple and easy to understand way.Derivation of First Equation of MotionThe first equation of motion is:v = u + atDerivation of First Equation of Motion by Algebraic MethodIt is KNOWN that the acceleration (a) of the body is defined as the rate of change of velocity.So, the acceleration can be written as:a = v − utFrom this, rearranging the terms, the first equation of motion is obtained, which is:v = u + atDerivation of First Equation of Motion by Graphical MethodConsider the diagram of the velocity-time graph of a body below:Derivation Of Equation Of MotionIn this, the body is moving with an initial velocity of u at point A. The velocity of the body then changes from A to B in time t at a uniform rate. In the above diagram, BC is the final velocity i.e. v after the body travels from A to B at a uniform acceleration of a. In the graph, OC is the time t. Then, a perpendicular is drawn from B to OC, a parallel line is drawn from A to D, and another perpendicular is drawn from B to OE (represented by dotted lines).Following details are obtained from the graph above:The initial velocity of the body, u = OAThe final velocity of the body, v = BCFrom the graph,BC = BD + DCSo, v = BD + DCv = BD + OA (since DC = OA)Finally, v = BD + u (since OA = u) (Equation 1)Now, since the slope of a velocity-time graph is equal to acceleration a,So,a = slope of line ABa = BD/ADSince AD = AC = t, the above equation becomes:BD = at (Equation 2)Now, combining Equation 1 & 2, the following is obtained:v = at + uDerivation of First Equation of Motion by Calculus MethodIt is known that,Derivation Of Equation Of MotionSo,Derivation Of Equation Of MotionDerivation of Second Equation of MotionThe second equation of motion is:S = ut + ½ a2Derivation of Second Equation of Motion by Algebraic MethodConsider the same notations for the derivation of the second equation of motion by simple algebraic method.Derivation Of Second Equation Of MotionDerivation of Second Equation of Motion by Graphical MethodTaking the same diagram used in first law derivation:Derivation Of Equation Of MotionIn this diagram, the distance travelled (S) = Area of figure OABC = Area of rectangle OADC + Area of triangle ABD.Now, the area of the rectangle OADC = OA × OC = utAnd, Area of triangle ABD = (1/2) × Area of rectangle AEBD = (1/2) at2 (Since, AD = t and BD = at)Thus, the total distance covered will be:S = ut + (1/2) at2Derivation of Second Equation of Motion by Calculus MethodVelocity is the rate of change of displacement.Mathematically, this is expressed as\(v=\frac{ds}{dt}\)Rearranging the equation, we get\(ds=vdt\)Substituting the first equation of motion in the above equation, we get\(ds=(u+at)dt\) \(=(udt+at\,dt)\) \(\int_{0}^{s}ds=\int_{0}^{t}u\,dt+\int_{0}^{t}at\,dt\) \(s=ut+\frac{1}{2}at^2\)Derivation of Third Equation of MotionThe third equation of motion is:v2 = u2 + 2aSDerivation of Third Equation of Motion by Algebraic MethodDerivation Of Third Equation Of MotionDerivation of Third Equation of Motion by Graphical MethodDerivation Of Equation Of MotionThe total distance travelled, S = Area of trapezium OABC.So, S= 1/2(SumofParallelSides)×HeightS=(OA+CB)×OCSince, OA = u, CB = v, and OC = tThe above equation becomesS= 1/2(u+v)×tNow, since t = (v – u)/ aThe above equation can be written as:S= 1/2(u+v)×(v-u)/aRearranging the equation, we getS= 1/2(v+u)×(v-u)/aS = (v2-u2)/2aThird equation of motion is obtained by solving the above equation:v2 = u2+2aSDerivation of Third Equation of Motion by Calculus MethodIt is known that,Derivation Of Equation Of MotionThese were the detailed derivations for equations of motion in the graphical method, algebraic method and calculus method.Equations of Motion FormulaEquations of motion FormulaFirst equation of motion v=u+atSecond equation of motion \(s=ut+\frac{1}{2}at^{2}\)Third equation of motion v2 = u2+2as |
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| 44. |
Why we take only two rays for constructing a ray diagram |
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Answer» o MAKE our concept clearer. We can also TAKE as many rays that we WANT but having many rays we can't make our concept crystal CLEAR. |
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| 45. |
A clock contain hour’s hand of length 14 cm. Calculate the displacement produced by the tip of thehand in the time of 9 hours is |
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Answer» he LENGTH of the lour hand is 14 cm.To find:Displacement of the hour hand in 9 hours.Solution:1) The length of the hour hand would be the radius of the circular PATH covered by the hand of the clock.2) Hand covers the TIME of 9 hours so it will COVER 3/4 of the total distance.3) So the displacement will be 3/4(2πr)3/2×πr3/2×22/7×1466 cm.Displacement of the hour hand in 9 hours is 66 cm. |
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| 46. |
State gauss law in electrostatics ? Derive coulomb law from gauss law |
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Answer» Gauss's law states that the net flux of an electric FIELD in a closed SURFACE is directly PROPORTIONAL to the enclosed electric CHARGE. ... It was initially formulated by Carl Friedrich Gauss in the year 1835 and relates the electric fields at the POINTS on a closed surface and the net charge enclosed by that surface. |
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| 47. |
Three point charges +q, +2q and xq are placed at the corners of an equilateral triangles of side of length r. Calculate x if the potential energy of the system is zero. |
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Answer» tion:given that the NET potential ENERGY of the SYSTEM is EQUAL to ZERO |
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| 48. |
Examples where the principle of moment is applied in daily life |
| Answer» TION:A force is applied to a door knob and the door swings open about its hinge. A driver can turn a steering wheel by applying a force on its rim. We utilise the turning effect of FORCES (moments) on a daily BASIS, for EXAMPLE when we USE devices such as levers. | |
| 49. |
Describe an experiment to show an electrical field pattern |
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Answer» "High VOLTAGE and TWO METAL plates /ELECTRODES Semolina and OIL in container Connect a (high) voltage to the plates in container Semolina lines up in the fieldSource: |
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